This study assessed the physicochemical quality of the creek and its phytoplankton diversity; samples were collected and analyzed for five months (May-September, 2018). The pH value recorded was within 6.95-7.53 but the total hardness recorded are above the WHO standard as a result of the presence of calcium, magnesium, sulphate arising from TSS, TDS, nutrient input. The level of chlorophyll-a increases with respect to pH, salinity, conductivity, water temperature, phosphate, sulphate and nitrate which reflected in the observed high DO and BOD5, an indication of the high rate of productivity of the water, the diversity and abundance of phytoplankton but negatively correlated with turbidity, TSS. However, the COD value exceeded the acceptable concentrations for a polluted water (20–200 mg/l). This is also confirmed with the presence of high amounts of indicator species like Microcystis spp., Euglena spp.,Phacus spp.and Trachelomonas spp. Measures should be taken to remediate the Ajegunle Creek .
Keywords: Creek, physicochemical quality, phytoplankton diversity
